The present invention relates to fluid jet devices. More particularly, the present invention is directed to a cover for fluid jet device heads to reduce the maintenance of the head and to improve the performance of certain jetted fluids.
Fluid jet devices are in wide-spread use. One major application of fluid jet devices is in inkjet printheads. These print heads are in wide-scale use from large industrial/commercial settings to small individual and consumer products.
Inkjet technology can be categorized as drop-on-demand and continuous jetting. In drop-on-demand printing, ink is jetted from the printhead (from a series of orifices in the head) onto a substrate. The ink is jetted or ejected as droplets in a discrete pattern to form a desired pattern, such as lettering, designs or bar codes, on the substrate. In continuous inkjet technology, ink droplets are continuously jetted and are directed, by use of a field, such as an electro-magnetic field, along a specific trajectory, to a substrate (to print) or into a gutter to be discarded.
Drop-on-demand technology can be further categorized as thermal inkjet technology, piezoelectric technology and valve-based technology. All of these technologies have certain advantages. For example, thermal technology provides high resolution with relatively low cost. Piezoelectric technology offers high jetting frequency, long lifetime, and the ability to jet a wide range of fluids.
Drop-on-demand (DOD) printing, although widely used, does have its drawbacks. For example, it is difficult to use quick-drying inks with DOD printing. These inks begin to dry rapidly, and have been found to, at times, begin drying before being ejected from the printhead orifice. This can result in the printhead orifices becoming partially or fully clogged, which can ultimately result in equipment shut downs for maintenance, repair or replacement.
Accordingly, there is a need for a device for a fluid jet device, such as a printhead, that enhances the performance of the fluid jetted from the device. Desirably, such an enhancement includes extending the life of the fluid and the usable life of the jetting device. More desirably, such a device is used in-line and has minimal or no adverse impact on the use of the jetting device.